Ovals? Possibly rounds (5)
I believe the answer is:
salvo
'rounds' is the definition.
(I have seen 'Several rounds' mean 'salvo' so perhaps 'rounds' could also mean 'salvo')
'ovals? possibly' is the wordplay.
'possibly' indicates an anagram.
'ovals' anagrammed gives 'SALVO'.
(Other definitions for salvo that I've seen before include "Fiery outburst" , "Ceremonial shots" , "concentrated fire" , "Simultaneous burst of fire" , "Sudden round of applause" .)